1. Field of the Invention
The present invention relates to an automatic tool changing device and a working machine. Specifically, the present invention relates to an automatic tool changing device for automatically changing a tool with respect to a spindle, and a working machine.
2. Description of Related Art
As an automatic tool changing device for automatically changing a tool with respect to a spindle of a machine tool, there has been known, for instance, an automatic tool changing device described in Japanese Patent Laid-Open Publication No. 2000-84777.
Such kind of automatic tool changing device has a tool magazine which can store a plurality of tools and position a tool to a predetermined tool delivery position, a rotating arm which has tool graspers at two ends thereof and is disposed between the delivery position of the tool magazine and a tool changing position in a rotatable manner, and a controller which controls a rotation operation and an advancing/retreating operation in the direction of the rotation axis of the rotating arm.
When performing a tool change, a designated tool is selected from the tool magazine, and the selected tool is positioned to the tool delivery position. At the same time, the spindle is positioned to the tool changing position. In this state, the rotating arm is rotated so that the tool graspers at two ends of the rotating arm respectively grasp the tools (which are the tool positioned to the tool delivery position and the tool mounted on the spindle). After that, the rotating arm is slid in the axial direction, rotated for 180 degrees, and slid in the axial direction, so that the tool positioned to the tool delivery position is mounted on the spindle and the tool mounted on the spindle is retrieved to the tool delivery position. In such a manner, the automatic tool change is performed.
In the conventional automatic tool changing device, when performing an automatic tool change, since the spindle has to be moved and positioned into a rotating area of the rotating arm, the automatic tool changing device has to be arranged in the vicinity of a machining area of the spindle if moving stroke of the spindle is small.
With such an arrangement, when the machining work by the spindle is performed under a machining condition in which, for instance, a lot of coolant liquid needs to be used, or a lot of chips are generated, the coolant liquid and chips will adhere on the automatic tool changing device, which may cause a failure.
To be able to arrange the machining area of the spindle and the automatic tool changing device separately from each other, the moving stroke of the spindle has to be increased, therefore the working machine itself will become large-sized and complicated, and economical disadvantage is generated.